Figure 4: Effects of the complex domain structure of BFO.
From: Giant elastic tunability in strained BiFeO3 near an electrically induced phase transition
(a) A phase-field simulated four-variant domain structure model (size: 128 × 128 × 50 nm3) for R-phase BFO/STO thin films. (b) Calculated bias evolution of local polarization component PZ underneath the tip, at various surface positions marked by the crosses in a and color-coded accordingly. (c) Distribution profiles of the in-plane strain component ɛ22 and polarization charge ρP (only for the dashed-line enclosed region; unit: 109 C m−3) for the pristine domain structure. Scale bar, 32 nm. (d) Lateral PFM domain image (200 × 200 nm2) of a domain junction region, on which a 20 × 20 BEPS mapping data set was acquired. Thick arrows denote the in-plane P vectors; the whole region has an upwards out-of-plane P direction except for a stripe region enclosed by green dashed lines. The cyan and yellow lines denote the surface traces of (100)- and (101)-domain walls, respectively. (e) Selected on-field piezoresponse loops acquired at the positions marked in d and color-coded accordingly; a map of the maximum piezoresponse is shown in the inset. (f) Map of the derived maximum resonance frequency shift, Δfc.r. a.u., arbitrary unit.
